I have a 2D space in which a function value is defined (you can think of it as a manifold). Now I plotted the function value using contourf and changed the colormap to something softer than jet. So far it looks quite good.
Now I want to draw a line representing the state over time in my space. That is also possible using the the plot command. But I want some more improvements: There is an additional state that is hidden for now (value 0...50). I would like the line color to change according to this hidden state. So in a sense to apply a separate colormap to the line plotted by plot like for example in a waterfall plot.
Is this (or something similar) possible using matlab?
Thanks
If you want to either use interpolated shading or have the colours change with the colour map, then you want to plot your data as a mesh and set the edgecolor property appropriately. Note that in order to plot it as a mesh, then you will need to duplicate it so that it has a size of at least 2 in each direction.
h = mesh([X(:) X(:)], [Y(:) Y(:)], [Z(:) Z(:)], [C(:) C(:)], ...
'EdgeColor', 'interp', 'FaceColor', 'none');
You may also want to look at the MeshStyle property, if you want to plot multiple lines simultaneously.
This solution is also much nicer than the one used in cline because it only creates one graphics object, rather than n.
Have a look into the cline.m function from file exchange, I think it is exactly what you need.
I can recommend the Colored line entry from the file exchange. It has good feedback and uses the color map to define the displayed colours, I've use it sucessfully on a number of projects.
Related
I am drawing several graphs in the same plot in matlab by using the command, hold on.
My problem is that I am drawing points with big markersize on top of some of the graphs, and I would like theses points to have some specific color. Only what happens is that some of them will take some color and some others take another color, my guess is that the colors of my points get mixed with the colors of the graphs on top of which i put them. Is there a mean to ask matlap to overwrite whatever is under my points so that they get the color I assign to them?
Example:
x= 0:1:10;
plot(x,x,'r',x,-x,'b','linewidth',2)
hold on
plot(5,-5,'.',10,10,'.','MarkerColor',[0,0.5,0],'Markersize',24)
hold on
plot(5,5,'.',10,-10,'.','MarkerFaceColor',[0,0.75,0],'MarkerSize', 24)
Imagine that the curves are much more complicated than theses simple lines so no way to start having fun cutting them each time I want to represent a point...
Now my problem is that I would like that the points 5,-5 and 10,10 to have the same color. Namely 0 0.5 0 dark green. but their color get mixed depending on which line they lie.
If I specify their color as '.g' I don't get this problem, but the problem is that I got too many points to get covered by the few number of colors that are labeled by letters (eg 'r' 'b' 'k' etc..).
Thankfully
Note that 'MarkerColor' doesn't exist, so I suppose it's a type and you meant 'MarkerFaceColor', just like in the other plot.
Then, hold on once is enough, you don't need to repeat it every time you want overlap another plot.
Finally, I suggest you simply use 'Color' instead of MarkerFaceColor. This should display your dots with the wanted color.
x= 0:1:10;
plot(x,x,'r',x,-x,'b','linewidth',2)
hold on
plot(5,-5,'.',10,10,'.','Color',[0,0.5,0],'Markersize',24)
plot(5,5,'.',10,-10,'.','Color',[0,0.75,0],'MarkerSize', 24)
I would like to scatter plot different sets of data points. Each point should have a different markerfacecolor, but within a given set, they would all have the same markeredgecolor.
I got this to work by looping over single scatter points individually, because markerfacecolor seems to only be able to take scalar points. The way I do it is that I loop through my data, and look for the appropriate color.
This works fine because I can define each point separately, but it becomes a problem when trying to set up the legend. It tries to list all the different points, but what I'd like is just an empty circle (markerfacecolor white or transparent), with each set having their specific markeredgecolor.
I hope this is clear enough. Thank you.
Mike
I've had luck using patches, setting 'FaceColor', 'EdgeColor' to 'none', 'MarkerEdgeColor' to 'flat' and setting the 'FaceVertexCData' to a Nx3 matrix where each row is a color corresponding the the points specified by you Nx1 'XData', 'YData' and 'ZData'.
h = patch('parent',gca,...
'XData',x,...
'YData',y,...
'ZData',z,...
'FaceColor','none',...
'EdgeColor','none',...
'MarkerFaceColor',faceColor,...
'MarkerEdgeColor','flat',... This is what sets the Edge of each marker
'FaceVertexCData',C) % C is a Nx3
I don't have access to Matlab at the moment, and Octave does not seem to have exactly the same functionality. Check out the Matlab patch properties documentation for more information.
how would one go about to get and use a color-coding from a variable to color a single quiver3 line?
I append a picture where i made a scatter plot in variable z that i would like the blue line emanating from there to be the same color. Is there a possibility?
Thanks.
Not with standard quiver. There's a file available on the File Exchange called quiverc, which uses the magnitude of the vector as the line color.
It's also not too hard to roll your own:
function colQuiver(xyz, uvw, cdata)
%// this makes it suitable for both 2D and 3D
xyz = num2cell(xyz);
uvw = num2cell(uvw);
for ii = 1:size(xyz,1)
L = cellfun(#(x,y) [0;x] + [y;y], ...
uvw(ii,:), xyz(ii,:),...
'Uniformoutput', false);
L = line(L{:});
set(L, 'color', cdata(ii,:));
end
end
Note that I didn't test this at all, there's no error checking, and you might want to allow other ways of specifying the color than just RGB values (use a LineSpec, via current colormap, ...)...But the essence it there ^_^
In case you are wondering for colored arrows:
QuiverS and Uquiver and Streakarrow3d. But none of them does what i want. They all have the arrows the same length and color coded, however i'd rather have them different lengths and color coded with yet another variable.
I'd really like to know if there's a way to add the colorbar properties we usually find in surface or mesh, but this time for a simple plot.
Thanx you!
Are you asking how to add a colorbar to a plot? The COLORBAR function does that, but it's really only useful if you have an object in your plot that uses a colormap, like a surface or an image.
For simple line plots, you're probably better off going with a legend.
In addition to what gnovice stated in their answer you can define your own colormap. I would suggest you model it off of a HSV scheme since you're wanting to vary the intensity. That was you can select the color you want and vary just the intensity value of it.
I would like to plot a vertical line (I'd prefer any orientation, but I'd be happy with just vertical right now) with two-color dashes, say red-blue-red-blue-...
I know I could do it like this:
plot([1,1],[0,1],'r'),
hold on,
plot([1,1],[0,1],'--b')
However, since I need to be able to move the line, among others, it should only have a single handle. How could I do this?
EDIT
Thank you for your answers. I guess I should indeed give some more information.
I have some data that is classified into different parts. I want to be able to manually adjust the boundaries between classes. For this, I'm drawing vertical lines at the classification boundaries and use draggable to allow moving the lines.
For the boundary between the red and the blue class, I'd like to have a red/blue line.
plot(ones(10,1),linspace(0,1,10),'-bs','MarkerFaceColor','r','MarkerEdgeColor','none','linewidth',6)
is what I'm actually using at the moment. However, it's not so pretty (if I want equal spacing, it becomes a real pain, and I want to give both colors the same weight), and I would like to have the possibility to use three colors (and not with marker edge and face being different, because it makes my eyes bleed).
Unfortunately, draggable does not allow me to use multiple handles, and grouping the lines with hggroup does not seem to create a draggable object.
cline looks like a promising approach, but rainbow colors won't work for my application.
You can use the code you have, and just concatenate the handles from each line into a vector of handles. When you want to change the properties of both lines simultaneously, the SET function is able to accept the vector of handles as an argument. From the documentation for SET:
set(H,'PropertyName',PropertyValue,...)
sets the named properties to the
specified values on the object(s)
identified by H. H can be a vector of
handles, in which case set sets the
properties' values for all the
objects.
Here's an example:
h1 = plot([1 1],[0 1],'r'); %# Plot line 1
hold on;
h2 = plot([1 1],[0 1],'--b'); %# Plot line 2
hVector = [h1 h2]; %# Vector of handles
set(hVector,'XData',[2 3]); %# Shifts the x data points for both lines
UPDATE: Since you mention you are using draggable from the MathWorks File Exchange, here's an alternate solution. From the description of draggable:
A function which is called when the
object is moved can be provided as an
optional argument, so that the
movement triggers further actions.
You could then try the following solution:
Plot your two lines, saving the handle for each (i.e. h1 and h2).
Put the handle for each in the 'UserData' property of the other:
set(h1,'UserData',h2);
set(h2,'UserData',h1);
Create the following function:
function motionFcn(hMoving) %# Currently moving handle is passed in
hOther = get(hMoving,'UserData'); %# Get the other plot handle
set(hOther,'XData',get(hMoving,'XData'),... %# Update the x data
'YData',get(hMoving,'YData')); %# Update the y data
end
Turn on draggable for both lines, using the above function as the one called when either object is moved:
draggable(h1,#motionFcn);
draggable(h2,#motionFcn);
I've never used it, but there's a submission by Sebastian Hölz called CLINE on the Mathworks File Exchange that seems related.
I don't know how to do exactly what you want, but presumably the reason you want to do this is to have some way of distinguishing this line from other lines. Along those lines, take a look at MathWorks' documentation on 2-D line plots. Specifically, this example:
plot(x,y,'--rs','LineWidth',2,...
'MarkerEdgeColor','k',...
'MarkerFaceColor','g',...
'MarkerSize',10)
should give you plenty of ideas for variation. If you really need the two-color dashes, it might help to specify why. That way, even if we can't answer the question, perhaps we can convince you that you don't really need the two-color dashes. Since you've already ruled out the over-lapping solution, I'm fairly certain there's no solution that answers all of your needs. I'm assuming the two-colorness is the most fluid of those needs.